The false carmine cochineal scale, Dactylopius opuntiae (Cockerell), Hemiptera: Dactylopiidae, is the most aggressive pest of Opuntia ficus-indica (L.) Mill, in many countries. The aim of this study is to evaluate the efficacy of culturable endorhizosphere bacteria isolated from the root of this cactus in terms of their potential antagonism as a biological control agent against this pest under laboratory and greenhouse conditions. Among 62 bacteria isolated from the cactus O. ficus-indica endorhizosphere, four bacterial isolates exhibited the highest insecticidal activities against nymphs and adult females of D. opuntiae. Under laboratory conditions, bacterial solutions of the strain 'BME8' Bacillus halotolerans and 'Bm3C' Priestia aryabhattai were sprayed onto D. opuntiae at concentrations 107 and 108 CFU.mL-1, respectively, which caused 100% mortality in adult females and nymphs within 24 h of treatment. While in greenhouse conditions, spraying the bacterial solution of the BME8 strain at 109 CFU.mL-1 on the covered cochineals, seemed to be the most effective, the number of insects declined by 59% after 7 days of application. The strain 'Bm4D' Bacillus licheniformis and 'Bm1A' Bacillus subtilis, played a key role in hydrolyzing the hydrophobic wax protecting females, which is the most important tool in controlling against D. opuntiae females. Furthermore, the strain 'Bm1A' Bacillus subtilis spray, was considered the second most efficient treatment in the greenhouse. The survival rate was 55% at 109 CFU.mL-1 after only 7 days of treatment. Enzymatic activity assays showed that all strains BME8, Bm1A and Bm4D (except Bm3C) exhibited alpha-amylase, pectinase and chitinase activities.